Completion apparatus and methods for use in hydrocarbon wells

Abstract

The present invention provides a cement shoe assembly for use on a string of tubulars in a well. In one aspect of the invention, the cement shoe assembly includes a housing having a lower portion with an enlarged inside diameter and a drillable cement shoe disposed therein. The shoe includes a weakened portion of material adjacent the enlarged inside diameter portion of the housing and ensures that as a cutting tool passes through the housing, all portions of the cement shoe are removed from the enlarged inside diameter portion, leaving a connection surface clear of debris for a subsequent tubular string. When a smaller tubular is expanded into the enclosed diameter portion of the housing, a connection is made therebetween without enlarging the outer diameter of the housing.

1. A cement shoe assembly for use in a wellbore comprising:
 a tubular housing for disposal at an end of a tubular string, the housing having an enlarged inner diameter portion at the lowermost end of the housing and a drillable material disposed in the enlarged inner diameter portion; and  
 a drillable cement shoe portion disposed in the housing, the cement shoe portion in selective fluid communication with the tubular string,  
 wherein the drillable material is predisposed to substantially fall away from the housing when drilled.  
 
   
   
     2. The cement shoe assembly of  claim 1 , wherein the drillable cement shoe includes a valve member providing the selective communication with the tubular. 
   
   
     3. The cement shoe assembly of  claim 1 , wherein the drillable material outside a reach of a cutting tool is predisposed to fall away from the housing upon passing the cutting tool through the housing. 
   
   
     4. A method of connecting a first tubular to a second tubular in a wellbore, the method comprising:
 providing a cement shoe assembly having a housing and drillable cement shoe, the assembly disposed at a lower end of a first tubular string;  
 cementing the housing in the wellbore by injecting cement into an annular area defined by the housing and a borehole therearound;  
 drilling the cement shoe to leave only the housing thereof, the housing having an area of increased inside diameter at a lower end thereof;  
 aligning an upper portion of the second tubular with the area of increased inside diameter of the housing; and  
 expanding the upper portion of the second tubular by placing a radially expansive force upon an inner wall thereof, until the second tubular is in frictional contact with the area of increased inside diameter of the housing and the outer diameter of the housing is not substantially expanded.  
 
   
   
     5. A cement shoe assembly for completion of a lined wellbore, the assembly comprising:
 a housing for disposal at a lower end of a tubular string, the housing having a first upper inside diameter and a lower, enlarged inside diameter;  
 a drillable shoe portion in the housing including: 
 a bore extending longitudinally therethrough for the selective passage of fluids;  
 drillable material disposed in an annular area between the bore and the inside surface of the housing, the drillable material selected from a list including cement, concrete, sand and composite materials;  
 a nose portion disposed on a lower end of the housing, the nose portion having at least one aperture therethrough; and  
 formations formed in the drillable material adjacent the lower, enlarged inside diameter portion of the housing, the formations constructed and arranged to urge the material away from the housing when the cement shoe is drilled.  
 
 
   
   
     6. A connection made in a wellbore between two tubulars, the connection comprising:
 a first tubular having an inside surface, the first tubular having an upset portion at its lower end wherein the first tubular decreases in wall thickness; and  
 a second tubular having an expanded diameter in contact with the inside surface of the first tubular, whereby the diameter of the first tubular is not substantially expanded and an inside diameter of both tubulars is substantially the same.  
 
   
   
     7. The connection of  claim 6 , wherein the inside surface of the first tubular is an enlarged diameter portion. 
   
   
     8. A method of forming a connection in a wellbore between a first, larger diameter tubular and a second, smaller diameter tubular without enlarging the diameter of the first tubular, comprising:
 providing the first tubular with an area of enlarged inside diameter at a lower end thereof, wherein a wall of the first tubular decreases in thickness at the area of enlarged inside diameter;  
 locating the second tubular coincident with the enlarged inside diameter of the first tubular; and  
 expanding the second tubular through use of radial force on an inside surface thereof, whereby  
 an outer surface of the second tubular expands outward to meet and frictionally contact the enlarged inside diameter portion of the first tubular without substantially enlarging the diameter of the first tubular.  
 
   
   
     9. The method of  claim 8 , wherein a hydraulically operated expander tool applies the radial force to the inside surface of the second tubular. 
   
   
     10. A method of forming a connection between two wellbore tubulars comprising the steps of:
 placing a first wellbore tubular having an outer diameter and a first end in proximity of a second wellbore tubular, the second wellbore tubular having an enlarged inner diameter portion formed by reducing a thickness of a wall of the second wellbore tubular at a second end, wherein the enlarged inner diameter portion is proximate the second end;  
 inserting the first end of the first tubular into the second end of the second tubular; and  
 expanding the first end of the first tubular, such that the outer diameter comes into connecting contact with the enlarged inner diameter portion.  
 
   
   
     11. The method of  claim 10 , wherein an expander tool with radially extendable members is used to expand the first end of the first tubular. 
   
   
     12. A cement shoe assembly for use in a wellbore, comprising:
 a tubular housing for disposal at an end of a tubular string, the housing having an enlarged inner diameter portion located at a lower end of the housing;  
 a drillable cement shoe portion disposed in the housing, the cement shoe portion in selective fluid communication with the tubular string; and  
 a drillable, nose portion disposed on a lower end of the housing to facilitate insertion of the assembly into the wellbore and having a bore therethrough substantially coincident with a bore of the cement shoe portion,  
 wherein the drillable material of the assembly adjacent the enlarged inner diameter portion of the housing is constructed and arranged to become dislodged from the housing when the shoe is drilled with a drill having an outer diameter smaller than the enlarged inner diameter portion of the housing and the drillable material is weakened by voids formed therein that terminate at an inner surface of the enlarged inner diameter portion of the housing.  
 
   
   
     13. The cement shoe assembly of  claim 12 , wherein the voids formed in the drillable material each extend radially from a point proximate a central tubular member to the inner surface of the enlarged diameter portion. 
   
   
     14. The cement shoe assembly of  claim 13 , wherein some of the drillable material is a composite material. 
   
   
     15. The cement shoe assembly of  claim 14 , wherein some of the composite material is fiberglass. 
   
   
     16. A method of forming a connection in a wellbore between a first, larger diameter tubular and a second, smaller diameter tubular without enlarging the diameter of the first tubular, comprising:
 providing the first tubular with an area of enlarged inside diameter at a lower end thereof, wherein the first tubular comprises a housing of a cement shoe;  
 locating the second tubular coincident with the enlarged inside diameter of the first tubular; and  
 expanding the second tubular through the use of radial force on the inside surface thereof, whereby  
 the outer surface of the second tubular expands outward to meet and frictionally contact the enlarged inside diameter portion of the first tubular without substantially enlarging the diameter of the first tubular.  
 
   
   
     17. A method of forming a connection between two wellbore tubulars comprising the steps of:
 placing a first wellbore tubular having an outer diameter and a first end in proximity of a second wellbore tubular having an enlarged inner diameter portion and a second end wherein the enlarged inner diameter portion is proximate the second end and the second tubular comprise a housing of a cement shoe;  
 inserting the first end of the first tubular into the second end of the second tubular; and  
 expanding the first end of the first tubular such that the outer diameter comes into connecting contact with the enlarged inner diameter portion.  
 
   
   
     18. A connection made in a wellbore between two tubulars, the connection comprising:
 a first tubular having an inside surface, wherein the inside surface is an enlarged inner diameter portion and the first tubular is a housing of a cement shoe; and  
 a second tubular having an expanded diameter in contact with the inside surface of the first tubular, whereby the diameter of the first tubular is not substantially expanded and an inside diameter of both tubulars is substantially the same.  
 
   
   
     19. The connection of  claim 18 , wherein the second tubular includes a string of tubulars, all of which have an expanded diameter. 
   
   
     20. A method of forming a connection in a wellbore between two tubulars, comprising:
 providing a second tubular and a first tubular having an enlarged inner diameter portion, the first tubular having a wall having a first thickness at a first portion and a second thickness at a second portion;  
 locating the second tubular coincident with the enlarged inner diameter portion of the first tubular; and  
 expanding the second tubular radially, such that an outer diameter of the second tubular frictionally contacts the enlarged inner diameter portion.  
 
   
   
     21. The method of  claim 20 , wherein the outer diameter of the second tubular frictionally contacts the enlarged inner diameter portion of the first tubular without substantially enlarging the diameter of the first tubular. 
   
   
     22. The method of  claim 20 , wherein the second thickness is less than the first thickness. 
   
   
     23. The method of  claim 22 , wherein the second portion is at the enlarged inner diameter portion. 
   
   
     24. The method of  claim 22 , wherein the second portion is at a lower end of the first tubular. 
   
   
     25. The method of  claim 22 , wherein the enlarged inner diameter portion is at a lower end of the first tubular. 
   
   
     26. A connection made in a wellbore between two tubulars, comprising:
 a first tubular having an inside surface, the first tubular having a wall having a first thickness at a first portion and a second thickness at a second portion; and  
 a second tubular having an expanded diameter in contact with the inside surface of the first tubular at the second portion, whereby the diameter of the first tubular is not substantially expanded and an inside diameter of both tubulars is substantially the same.  
 
   
   
     27. The connection of  claim 26 , wherein the second thickness is less than the first thickness. 
   
   
     28. The connection of  claim 27 , wherein the second portion of the wall of the first tubular is an enlarged inner diameter portion. 
   
   
     29. The connection of  claim 27 , wherein the second portion is at a lower end of the first tubular. 
   
   
     30. A cement shoe assembly for use in a wellbore comprising:
 a tubular housing for disposal at an end of a tubular string, the housing having an enlarged inner diameter portion at the lowermost end of the housing;  
 a drillable cement shoe portion disposed in the housing, the cement shoe portion in selective fluid communication with the tubular string; and  
 a drillable, nose portion disposed on the lowermost end of the housing to facilitate insertion of the assembly into the wellbore, the nose portion having a bore therethrough substantially coincident with a bore of the cement shoe portion.  
 
   
   
     31. The cement shoe assembly of  claim 30 , wherein a drillable material of the assembly adjacent the enlarged inner diameter portion of the housing is constructed and arranged to become dislodged from the housing when the shoe is drilled with a drill having an outer diameter smaller than the enlarged inner diameter portion of the housing. 
   
   
     32. The cement shoe assembly of  claim 31 , wherein the drillable material is weakened by voids formed therein. 
   
   
     33. A cement shoe assembly for use in a wellbore comprising:
 a tubular housing for disposal at an end of a tubular string, the housing having an enlarged inner diameter portion at the lowermost end of the housing;  
 a drillable cement shoe portion disposed in the housing, the cement shoe portion in selective fluid communication with the tubular string; and  
 a drillable material adjacent the enlarged inner diameter portion of the housing constructed and arranged to become dislodged from the housing when the shoe is drilled with a cutting tool having an outer diameter smaller than the enlarged inner diameter portion of the housing.